Pool cleaners vary widely in degree of sophistication. Existing products range from simple brushes to automatic cleaners with self-propelled vacuum heads. In many designs, the pool's circulation system is used to create the vacuum at the vacuum head in addition to filtering the influent water. In others, the vacuum may be created by applying pressurized water to the device and a filter may be contained on the vacuum head.
The most basic type of pool cleaning device consists of a brush mounted to a pole. This device operates by loosening dirt particles from the pool surfaces, thereby causing them to be suspended in the pool water. These particles are then removed from the water by the pool circulation system. This system can also be used to clean spas which either have their own circulation intake port, of have the capability to "pour over" into the water of an adjacent swimming pool. This cleaning method assumes that after the pool surfaces are brushed, the dirt particles will be removed by the pool circulation system before they settle back down on the pool surfaces.
A more efficient cleaning method provides for a water powered vacuum so that dirt particles will be removed from the pool at the point where they are disturbed by the cleaning device. A water powered vacuum can be powered in either of two ways. One way is to connect the vacuum head to the pump inlet of the pool's circulation system via a suction hose. The second way is by applying a stream of pressurized water to the vacuum head through a suitable hose. With the first method, the water is filtered by the pool's circulation system. Under the second method, a filter located on the device can be used to clean the water before it is returned to the pool, or the device can place dirt particles in suspension in the pool for removal by the filter in the pool circulation system. A water powered vacuum head may be equipped with brush bristles to dislodge dirt particles, or with wheels so that the head can be rolled along the pool surfaces.
A common way to implement this latter class of device is to hinge mount the vacuum head to the end of a pole. The user can then operate and maneuver the vacuum head without getting wet. Existing devices require two connections to be made to the vacuum head, one for the pole, and the other for either the suction hose or the pressurized water hose.
These manual pool cleaners have several drawbacks when used to clean spas. The vacuum heads equipped with wheels are too cumbersome, even when flexible, to efficiently clean smaller and more contoured surfaces. When a vacuum brush head is used, the pole is connected off center of the head toward the user side of the brush. This tends to result in unbalanced brush strokes. Both the suction type and the eduction type cleaners are inconvenient to use when they must be removed from the pool water. These situations occur when the cleaner must be moved from the pool to a spa. In devices that use the pool circulation system, the prime of the circulation pump must be maintained; movement of the vacuum head to a spa from a pool typically is done by shutting down the pump, disconnecting the hose from the vacuum head, holding one's hand over the exposed end of the suction hose to keep the hose filled with water, and then moving over to the spa where, underwater, either the pool head is reconnected to the hose or a head sized for spas is connected to the hose, after which the pump is restarted. When an eduction-type vacuum head is used, the user runs the risk of being sprayed by the discharge of the pressurized water each time the head is removed from the pool water. Obviously, this can be avoided by turning off the external water supply each time the device is removed from the pool or spa water. However, when cleaning shallow surfaces, the discharge port of an eduction type vacuum head may frequently be inadvertently removed from the water, thus spraying the user.
Automatic pool cleaners move about the under water pool surfaces without the aid of a person. The vacuum effect in the cleaner head may be created by either of the methods previously described. The principle drawbacks to automatic pool cleaners are that they do not effectively clean the highly contoured areas around steps and they cannot be used in small areas such as spas.